1. Field of the Invention
The present invention relates to a method for providing a channel service, and more particularly to a method for providing a channel service wherein a fixed information and a variable information associated with a streaming data of a channel service are transmitted to a playback apparatus supporting a BD-J specification to enable a streaming of the channel service.
2. Description of the Related Art
A Blu-ray specification is designed by Blu-ray Disc Association (“BDA”), whose members include Sony, Hitachi and Sharp. The Blu-ray specification includes a specification of a Blu-ray disk which is an optical disc that may be read and recorded using a blue laser.
While a diameter and a thickness of the Blu-ray disk, which are 12 cm and 1.2 mm, respectively, are same as those of conventional CD (Compact Disc) and DVD (Digital Versatile Disc), a storage capacity thereof is larger than those of the conventional CD and DVD.
Because the blue laser having a wavelength of 405 nm is used for reading the Blu-ray disk instead of a red laser having a wavelength of 650 nm used for reading the DVD, more data can be stored in the Blu-ray disk than the DVD.
Specifically, a single layer Blu-ray disk is capable of storing up to 25 GB of a data and a dual layer Blu-ray disk is capable of storing up to 50 GB of the data. This means that the Blu-ray disk can store five times more data than the DVD.
Moreover, a quad layer Blu-ray disk and an octal layer Blu-ray disk can store up to 100 GB and 200 GB, respectively.
The Blu-ray disk supports a video compression codec of MPEG-2 which is widely used in the DVD. Moreover, BDA standard specification requires the Blu-ray disk to use H.264/AVC or VC-1 as the video compression codec which provides improved compression ratio compared to MPEG-2.
In addition, the Blu-ray disk supports audio formats such as Dolby Digital Plus, Dolby TrueHD and DTS-HD Master Audio as well as PCM (Pulse-code modulation), Dolby Digital and DTS.
A Blu-ray player supporting a BD-J specification supports an interactive service based on JAVA. Moreover, the Blu-ray player supporting the BD-J specification supports a network connectivity, a PIP(Picture-In-Picture) and a connection to a local storage.
A Blu-ray player supporting a BD-Live specification is capable of playing the streaming data received through a network communication in addition to capabilities of the Blu-ray player supporting a BD-J specification.
A Virtual File System (“VFS”) enables a playback of a data which is not stored in the Blu-ray disk. Specifically, the VFS configures a virtual package on the Blu-ray player to enable the Blu-ray player to play the streaming data received through a USB or the network communication as if the streaming data is stored in the Blu-ray disk.
Hereinafter, “a playback apparatus supporting the BD-J specification” includes the Blu-ray player supporting the BD-J specification or an apparatus using a middleware supporting the BD-J specification such as a TV, a set-top box, a PMP (Portable Multimedia Player), a video game console, a PC (Personal Computer) and a PVR(Personal Video Recorder).
The apparatus using the middleware supporting the BD-J specification is not required to have a Blu-ray disk reading capability.
FIG. 1 is a diagram illustrating a configuration for providing an audio/video data in accordance with a conventional method.
A content providing server generates a BUMF (Binding Unit Manifest File) information, an SF (Signature File) information, a playlist information, a clip information and a movie clip according to the BD-J specification.
The BUMF information defines a configuration of a virtual package in XML (Extensible Markup Language) format. For instance, the BUMF information includes a file name information and a binding information on the movie clip included in the audio/video data received from the content providing server.
The SF information is used for verifying a validity of the BUMF information. The SF information uses SHA (Secure Hash algorithm)-1.
The playlist information includes an information on the audio/video data to be played. For instance, the playlist information includes a playback sequence information, a PlayItem information and a PlayListMark information on the movie clip included in the audio/video data.
The clip information includes an information required for playing the movie clip. For instance, the clip information includes a stream format information of the corresponding clip, a number of packets included in the corresponding clip, an encoding specification of the corresponding clip and a time stamp information.
The playback apparatus stores the BUMF information, the SF information, the playlist information and the clip information received from the content providing server in a BUDA (Binding Unit Data Area). The playback apparatus carries out a package update from a disk package to the virtual package based on the BUMF information, the SF information, the playlist information and the clip information stored in the BUDA. That is, the playback apparatus is configured to play the audio/video data received from the content providing server instead of playing a data stored in the Blu-ray disk.
When the playback apparatus is fully configured, the playback apparatus receives and plays the audio/video data from the content providing server.
In order to play the audio/video data received from the content providing server, the playback apparatus must identify a size of the audio/video data, the number of clips included in the audio/video data, a encoding algorithm of the clip and a validity verification information by receiving the BUMF information, the SF information, the playlist information and the clip information from the content providing server.
However, in case of the channel service such as a live broadcasting wherein the audio/video data is continuously generated and transmitted in real time, the BUMF information, the SF information, the playlist information and the clip information cannot be generated for the audio/video data that constantly changes with time.
Without the BUMF information, the SF information, the playlist information and the clip information, the playback apparatus cannot carry out the package update from the disk package to the virtual package. As a result, the audio/video data of the channel service cannot be played by the playback apparatus.